I have my MacPro Quad and upgraded to Mountain Lion. I have cloned the system hard disk to bootable external HD. I have tried it and works fine. Now when I have put the external HD in the BAY I to use it as my main HD the booting time is very long. How can I reduce the booting time? Many thanks in advance for your assistance. Michel
Since you have moved the system disk around, the Mac doesn't know where it is so it takes a few seconds to look for it. You need to tell the system which disk will be the boot disk and where it is located. After you have moved the disk to the bay, Open the System Preferences>Startup Disk window and choose the bay disk. When you restart, the Mac will know exactly where the boot disk is and your bootup time will be a lot faster.